Focalboard IDOR in file content endpoint allows cross-user file access (unsupported product, no fix)
Priority LOW 20CWE-639Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-639.
Summary
** UNSUPPORTED WHEN ASSIGNED ** Focalboard version 8.0 fails to validate file ownership when serving uploaded files. This allows an authenticated attacker who knows a victim's fileID to read the content of the file. NOTE: Focalboard as a standalone product is not maintained and no fix will be issued.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0023 13th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Mattermost | Focalboard | up to 8.0 | — | No fix listed | CNA |
| — | github.com/mattermost/focalboard (Go) | up to 7.10.6 | — | No fix listed | GHSA-vph7-r229-qxpf |
- Focalboard VendorMattermost Affected up to 8.0 Fixed in — No fix listed CNA
- github.com/mattermost/focalboard (Go) Vendor— Affected up to 7.10.6 Fixed in — No fix listed GHSA-vph7-r229-qxpf
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mattermost:focalboard:8.0.0:*:*:*:*:*:*:* | 8.0.0 | Vulnerable | Mattermost |
- cpe:2.3:a:mattermost:focalboard:8.0.0:*:*:*:*:*:*:* Versions 8.0.0 Vulnerable ·Mattermost
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-28736
- 2026-10-03 Alias added: GHSA-vph7-r229-qxpf
References
More Mattermost Focalboard vulnerabilities
- TI-2026-20840 SQL injection in Mattermost Focalboard CVSS 3.1HIGH 8.1
Sources
- CVE-2026-28736 · CVE Program
- CVE-2026-28736 · NVD
- FIRST EPSS
- GHSA-vph7-r229-qxpf · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences